KR101612900B1 - Apparatus for controling cold spray coating - Google Patents

Abstract

The present invention relates to a low-temperature spray controller, and more particularly, to a low-temperature spray controller that includes a gas supply portion including a gas reservoir and a gas preheater, a powder feed portion including a powder feeder and a powder preheater, a powder spray portion for mixing gas and powder, A pressure control means for detecting and controlling the temperature, and a temperature control means for detecting and controlling the temperature of the gas and the powder. Therefore, the present invention provides a gas preheater and a powder preheater, and by controlling the pressure of the gas and the temperature of the gas and the powder, it is possible to stably maintain the pressure and the temperature Can be controlled.

Low Temperature, Spray, Coating, Control

Description

[0001] Apparatus for controlling cold spray coating [0002]

More particularly, the present invention relates to a low temperature injection control device for controlling the injection and coating of a material to be coated in a low temperature region, which is a room temperature or a similar temperature at which a material reacts or a structure of a material is not changed .

Cold spray coating is one of spray coating methods in which powder to be coated is sprayed and coated. One of the spray coating methods is the melt spray coating method (thermal spray coating). However, such a melt spray coating method is a method in which the material to be coated is melted at a high temperature in advance and sprayed on the surface of the object, The coating material can be easily coated because of melting and spraying.

Generally, such a spray coating method is widely used, but it is not applicable to a case where a problem occurs in that when the material is melted at a high temperature, a material reacts, a high temperature structure is formed, and a coating layer to be finally obtained is not obtained.

In order to solve this problem, a low temperature spray coating method has been proposed. In contrast to the melt spray coating method, the low temperature spray coating method is applied to a material to be coated at a low temperature region, which is a room temperature or a similar temperature, Followed by spraying.

Thus, there is a problem that coating workability of materials to be sprayed is lowered when spray coating is performed at a low temperature. That is, when the material is coated by the spray coating method, since the material is melted and injected at a high temperature, a phenomenon that the material is diffused or fused at a high temperature between the object and the coating material as well as between the material and the coating material occurs to obtain a solid coating layer on the surface of the object have.

However, in the case of the low temperature spray coating method, unlike the spray coating method, since the temperature of the coating material is low, it is difficult to expect a phenomenon such as high temperature diffusion or fusion between the coating materials or between the object and the coating material. In order to overcome these problems, it is necessary to maximize the speed of the coating material so that the kinetic energy of the coating material can provide a bonding force between the coating materials or between the object and the coating material when performing the low temperature spray coating method.

In addition, when coating is performed using a low-temperature injection process, since the low-temperature spray process is fundamentally a solid-state process, it can not be coated with a ceramic material, and coating is good with tough copper, nickel, and aluminum.

However, alloys with reduced toughness, cermets such as WC-Co, etc. have poor coating properties, which increases the critical velocity at which coating begins. To solve this problem, there is a problem that gas consumption is increased by increasing the gas pressure by increasing the gas pressure.

In order to increase the gas velocity, a method of preheating the gas may be used. However, this method not only increases the electric consumption but also has a disadvantage that the life of the gas preheating tube is shortened as the temperature increases. In addition, if air is heavier than nitrogen, use of helium can lead to an increase in gas velocity, but the cost of helium gas is high, resulting in poor economics.

Since the low-temperature injection process is basically a lamination process by plastic deformation of a metal material, as the toughness of the coating material increases, the lamination rate and the coating property are improved. As the metal temperature increases, the toughness is increased. If the preheating is used before, the high laminating ratio and the excellent coating layer can be obtained under the same low temperature injection process condition, but a stable temperature control technique is required to realize this.

In order to stably control the preheating of the powder, the temperature control inside the preheater must be stably controlled. Since the characteristics of the low temperature spray coating must keep the gas and the powder flowing while the powder and gas are preheated to a predetermined temperature, There is a problem that takes a long time.

Such a conventional powder heater uses a Kanthal mounted on the inner wall of the heater to raise the ambient temperature and flow through a tube mounted in the heater to heat the powder and gas.

Accordingly, the conventional powder heater has a problem in that excessive PID control is not smoothly performed to raise the temperature to a desired temperature within a short time in order to reduce the overall gas and powder consumption, resulting in excessive overheating and hunting phenomenon.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to control the pressure and temperature stably so as to reduce consumption of gas and powder at an initial temperature and pressure of a low temperature injection process, It is an object of the present invention to provide a low temperature injection control device capable of achieving a high deposition rate and an excellent coating layer and capable of easily controlling the pressure and temperature of an initial state of gas and powder as well as preventing excessive overheating and hunting phenomenon It is for that purpose.

According to an aspect of the present invention, there is provided a gas purifier comprising: a gas storage unit for storing a gas; a gas supply unit provided downstream of the gas storage unit and including a gas preheater for heating the gas provided therein; A powder feeder disposed downstream of the powder feeder and having a powder preheater for heating a gas provided from the gas storage tank and a powder provided from the powder feeder; A powder spraying unit installed downstream of the gas supply unit and the powder supply unit and mixing and spraying the gas and powder supplied thereto; And a control unit including pressure control means for detecting and controlling the pressure of the gas, and temperature control means for detecting and controlling the temperature of the gas and the powder.

The pressure control means of the present invention includes a first pressure sensor provided in the powder spraying portion and detecting a pressure in a mixed state of gas and powder, a second pressure sensor for detecting a pressure of the gas provided to the gas preheater, A third pressure sensor for detecting the pressure of the gas supplied to the powder feeder, and an on-off valve and a regulator for controlling the pressure of the gas.

The temperature control means of the present invention may further comprise a first temperature sensor for detecting the temperature of the powder spraying portion, a second temperature sensor for detecting the temperature of the gas preheater, a third temperature sensor for detecting the temperature of the powder preheater, , An SCR and a PID controller for controlling the temperature of the gas and the powder.

As described above, the present invention provides a gas preheater and a powder preheater, and controls the gas pressure and the temperature of the gas and the powder to reduce the consumption of gas and powder at the initial temperature and pressure of the low temperature injection process It provides the effect of stable pressure and temperature control.

In addition, the powder to be coated can be preheated before coating to obtain a high laminating ratio and an excellent coating layer in the same low temperature spraying process.

In addition, the pressure control means includes a pressure sensor, an on-off valve, and a recirculator to easily control the pressure to the initial state of the gas, and to prevent excessive overheating and hunting.

Also, the temperature control means includes the temperature sensor, the SCR and the PID controller to easily control the temperature of the gas and the powder in the initial state, and to prevent excessive overheating and hunting phenomenon.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a block diagram showing a control state of the low-temperature emission control device according to an embodiment of the present invention, and FIG. 3 is a block diagram showing the control state of the low-temperature emission control device according to the embodiment of the present invention. 1 is a signal flow diagram illustrating a signal flow of a low temperature injection control apparatus according to an embodiment of the present invention.

As shown in FIGS. 1 and 2, the low temperature emission control apparatus of this embodiment includes a gas supply unit including a gas storage tank 100, a gas booster 200 and a gas preheater 400, a powder feeder 500, A controller 300 and a powder sprayer 700. The cold spray coating is performed on the surface of the object with powder.

That is, the low-temperature spray controller of the present embodiment is operated by a high-pressure nitrogen gas or air heated through a gas preheater and a powder preheater, and then compressed at a nozzle inlet and introduced into a supralateral nozzle of de Lavel type, The expansion to the atmospheric pressure occurs and the supersonic flow is generated. Due to such a principle, the low-temperature spray controller of the present embodiment allows the surface of the object to be coated with the powder sprayed at a high speed.

The gas supply unit includes a gas storage tank 100 for storing a gas, a gas booster 200 installed downstream of the gas storage tank 100 to increase the pressure of the gas supplied thereto, A gas preheater 400 installed downstream of the gas booster 200 and heating the provided gas.

The gas reservoir 100 includes a gas generator to store the generated gas. This gas is helium (He), nitrogen (N _2), or air may be formed of a mixture thereof.

The gas booster 200 increases the pressure of the gas supplied from the gas storage tank 100 and supplies the gas to the control unit 300 so that the gas is supplied to the gas preheater 400 and the powder feeder 500 under the control of the controller 300 .

The gas preheater 400 is a gas heater installed downstream of the control unit 300. The gas preheater 400 heats the gas supplied by the control unit 300 to a predetermined temperature and supplies the heated gas to the powder spray unit 700.

The powder feeder includes a powder feeder 500 that feeds powder and a powder that is installed downstream of the powder feeder 500 to heat the gas provided from the gas storage tank 100 and the powder provided from the powder feeder 500 together And a preheater 600.

The powder feeder 500 is a powder feeder installed downstream of the controller 300 and supplies the gas supplied by the control unit 300 to the powder preheater 600 together with a predetermined amount of powder.

Such powders may be composed of powders of various materials such as aluminum (Al), copper (Cu), nickel (Ni), zinc (Zn), tin (Sn) or ceramic composite depending on the material of the low temperature spray coating object Of course.

The powder preheater 600 is a powder heater disposed downstream of the powder feeder 500. The powder preheater 600 heats the powder supplied from the gas storage tank 100 and the powder supplied from the powder feeder 500 to a predetermined temperature, ).

The powder spraying unit 700 is a spray nozzle for spraying powder, which is installed downstream of the gas preheater 400 of the gas supply unit and the powder preheater 600 of the powder supply unit, and mixes the gas and powder supplied thereto, The powder is sprayed on the surface to be coated.

It is preferable that a supersonic nozzle such as a de Laval nozzle is used as the powder jetting part 700 in which the inner diameter of the nozzle decreases from the inlet side and the inner diameter of the nozzle increases from a certain position.

The control unit 300 includes a microcomputer 310, a main SCR 320, a main PID 321, a main SCR 320, and a main PID 320. The control unit 300 includes a pressure control unit for detecting and controlling the pressure of the gas and a temperature control unit for detecting and controlling the temperature of the gas and the powder. A controller 330, a powder SCR 340, a powder PID controller 350, and an HMI 360.

The microcomputer 310 is a main control means having functions of CPU, RAM, ROM, TIMER, A / D and the like in one IC. The main processor PID controller 311 and the main processor PID controller 310 provide control signals for various controllers. And a powder process PID controller (312).

The HMI 360 (Human Machine Interface) such as a push button switch for operating a switch, a selector for selecting one of several functions, various instruments, etc. is connected to the microcomputer 310 via a communication line 361 such as RS232C .

The main SCR 320 is a silicon controlled rectifier (SCR) that controls the gas preheater 400 and controls the current supplied to the gas preheater 400 to control the gas preheater 400 do.

The main PID controller 330 is a PID controller that controls the gas preheater 400 and controls the heating temperature of the gas preheater 400 to a predetermined temperature.

The powder SCR 340 is a silicon controlled rectifier that controls the powder pre-heater 600 and controls the powder pre-heater 600 by controlling the current supplied to the powder pre-heater 600. The powder PID controller 350 is a PID controller for controlling the powder pre-heater 600, and controls the heating temperature of the powder pre-heater 600 to a predetermined temperature.

The human machine interface (HMI) 360 comprises a push button switch for operating the switch, selectors for selecting one of several functions, various instruments, and the like, and manually inputs various control signals and control values to the microcomputer 310 .

The pressure control means includes a first pressure sensor P1 provided in the powder spraying portion 700 for detecting the pressure in the mixed state of gas and powder and a second pressure sensor P1 for detecting the pressure of the gas supplied to the gas preheater 400 A third pressure sensor P3 for detecting the pressure of the gas supplied to the powder feeder 500, on / off valves 371 and 381, regulators 372 and 382, And a valve 373.

The first pressure sensor P1 is installed in the powder sprayer 700 and detects the pressure of the mixed gas and powder supplied to the first pressure sensor P1 and transmits the detected pressure to the microcomputer 310. [

The second pressure sensor P2 is installed in the gas inlet pipe of the gas preheater 400, detects the pressure of the gas supplied thereto, and transmits the detected pressure to the microcomputer 310.

The third pressure sensor P3 is installed in the gas inflow pipe of the powder feeder 500, detects the pressure of the gas supplied thereto, and transmits the detected pressure to the microcomputer 310.

The on / off valves 371 and 381 are connected to the on / off valve 371 for the gas preheater installed in the gas inflow pipe of the gas preheater 400 and the gas preheater installed in the gas inflow pipe of the powder feeder 500 Off valve 381 to open and close the gas inflow pipe of the gas preheater 400 and the gas inflow pipe of the powder feeder 500, respectively.

Regulators 372 and 382 are composed of a regulator 372 for the gas preheater installed in the gas inlet pipe of the gas preheater 400 and a regulator 382 for the powder preheater installed in the gas inlet pipe of the powder feeder 500, The amount of gas flowing into the gas inflow pipe of the gas preheater 400 and the gas inflow pipe of the powder feeder 500 is controlled.

The check valve 373 is installed in the gas inflow pipe of the control unit 300 to allow the inflow of the gas into the control unit 300 only to prevent backflow of the gas.

The temperature control means includes first temperature sensors TC1 and TC2 for detecting the temperature of the powder spraying section 700, second temperature sensors TC3 and TC4 for detecting the temperature of the gas preheater 400, Third temperature sensors TC5 and TC6, SCRs 320 and 340, and PID controllers 330 and 350 for detecting temperatures of the first and second temperature sensors 600 and 600, respectively.

The first temperature sensors TC1 and TC2 include a gas temperature detection sensor TC1 for detecting the gas temperature of the powder injecting section 700 and a powder temperature detecting sensor TC2 for detecting the powder temperature of the powder injecting section 700, And detects the gas temperature and the powder temperature of the powder sprayer 700 and transmits the detected temperature to the microcomputer 310.

The second temperature sensors TC3 and TC4 are provided with a gas discharge temperature detecting sensor TC3 for detecting the temperature of the gas discharge pipe of the gas preheater 400 and a gas preheating temperature detecting sensor for detecting the temperature of the gas preheater 400 Sensor TC4 and detects the gas discharge temperature and the gas preheating temperature of the gas preheater 400 and transmits them to the microcomputer 310. [

The third temperature sensors TC5 and TC6 include a powder discharge temperature detecting sensor TC5 for detecting the temperature of the powder discharge pipe of the powder preheater 600 and a powder preheating temperature detecting sensor TC5 for detecting the temperature of the powder preheating pipe of the powder preheater 600. [ And a sensor TC6 to detect the powder discharge temperature and the powder preheating temperature of the powder pre-heater 600 and transmit the detected temperature to the microcomputer 310. [

The SCRs 320 and 340 generate a current control signal for the gas preheater 400 transmitted from the microcomputer 310 based on the detection results of the first temperature sensors TC1 and TC2 and the second temperature sensors TC3 and TC4 A current control for the powder preheater 600 transmitted from the microcomputer 310 based on the detection results of the first temperature sensors TC1 and TC2 and the third temperature sensors TC5 and TC6, And a powder SCR 340 that implements the signal.

The PID controllers 330 and 350 control the temperature of the gas preheater 400 transmitted from the microcomputer 310 based on the detection results of the first temperature sensors TC1 and TC2 and the second temperature sensors TC3 and TC4, The main PID controller 330 that implements the main PID controller 330 and the powder preheater 600 transmitted from the microcomputer 310 based on the detection results of the first temperature sensors TC1 and TC2 and the third temperature sensors TC5 and TC6. And a powder PID controller 350 that implements a temperature control signal.

In addition, a mixing chamber is provided downstream of the gas preheater 400 and downstream of the powder preheater 600 to mix the preheated gas and the preheated powder at a certain ratio in the mixing chamber, The powder may be injected into the powder spraying unit 700 and sprayed onto the surface of the object.

3, the signal flow of the low temperature emission control apparatus of the present embodiment is controlled by the first pressure sensor P1, the second pressure sensor P2 and the third pressure sensor P3, The gas preheater 400 and the powder preheater 600 are detected and transmitted to the microcomputer 310. The first temperature sensors TC1 and TC2, the second temperature sensors TC3 and TC4, the third temperature sensor TC5 The gas preheater 400 and the powder preheater 600 are detected by the control unit TC6 and transmitted to the microcomputer 310. [

The microcomputer 310 controls the main processor PID controller 311, the main PID controller 330 and the gas preheater regulator 372 to control the supply amount of the gas based on the detected values of the pressure sensor and the temperature sensor. And transmits a control signal to the main SCR 320. [

The microcomputer 310 further includes a powder feeder 500, a powder processor PID controller 312, a powder PID controller 350, and a powder pre-heater 350 to control an inflow amount of the powder based on the detected values of the pressure sensor and the temperature sensor. And sends a control signal to the powder SCR (340).

The low temperature injection control device of this embodiment can reduce the consumption of gas and powder at the initial temperature and pressure of the low temperature injection process by installing a gas preheater and a powder preheater and controlling the gas pressure and the temperature of gas and powder So that high lamination rate and excellent coating layer can be obtained in the same low temperature injection process.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Therefore, the above embodiments are merely illustrative in all respects and should not be construed as limiting.

1 is a block diagram showing a configuration of a low temperature injection control apparatus according to an embodiment of the present invention;

2 is a block diagram showing a control state of the low temperature emission control device according to one embodiment of the present invention.

3 is a signal flow diagram illustrating a signal flow of a low temperature injection control apparatus according to an embodiment of the present invention.

Description of the Related Art

100: gas storage tank 200: gas booster

300: control unit 400: gas preheater

500: powder feeder 600: powder preheater

700: Powder jetting part

Claims (3)

A gas booster provided downstream of the gas storage tank for increasing the pressure of the gas provided from the gas storage tank; a gas preheater installed downstream of the gas storage tank for heating the gas provided from the gas storage tank; A gas supply unit having a gas supply unit; A powder feeder disposed downstream of the powder feeder and having a powder preheater for heating a gas provided from the gas storage tank and a powder provided from the powder feeder; A powder spraying part connected to the gas preheater and the powder preheater to mix and spray the gas and powder supplied from the gas preheater and the powder preheater; And Pressure control means for detecting and controlling the pressure of the gas, and a temperature control means for detecting and controlling the temperature of the gas and the powder, Wherein the pressure control means comprises: A second pressure sensor installed in the gas preheater and detecting a pressure of a gas provided to the gas preheater; a second pressure sensor installed in the gas preheater to detect a pressure of the mixed state of the gas and the powder; A third pressure sensor installed in the feeder for detecting the pressure of the gas supplied to the powder feeder, an on-off valve and regulator for the gas preheater installed in the gas inflow pipe of the gas preheater, and a gas inflow pipe Off valve and a regulator for the powder preheater, The temperature control means includes a first temperature sensor installed in the powder spraying portion and detecting the temperature of the powder spraying portion, a second temperature sensor installed in the gas preheater to detect the temperature of the gas preheater, And a third temperature sensor for detecting the temperature of the powder pre-heater. The method according to claim 1, Wherein the second pressure sensor is installed in a gas inflow pipe of the gas preheater and the third pressure sensor is installed in a gas inflow pipe of the powder feeder. The method according to claim 1, Wherein the temperature control means further comprises a Silicon Controlled Rectifier (SCR) and a PID controller for controlling the temperature of the gas and the powder.

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